In the related art, a continuous heating furnace including a plurality of gas heaters used to heat a radiator with combustion heat generated by combusting a fuel gas and heating an industrial material, food, or the like, with radiant heat from a radiation surface of the radiator has been widely distributed.
The continuous heating furnace drives a conveyance body such as an endless belt or the like and burns a burning target while conveying the burning target in a heating space in a furnace main body. A portion of the conveyance body is cooled at the outside of the furnace main body (a heating space), and heat in the heating space is radiated to repeat a cycle of absorbing heat in the furnace main body. This causes a decrease in thermal efficiency of the continuous heating furnace. Here, a configuration of the heating furnace in which a conveyance portion of a conveyance body conveyed from a downstream side to an upstream side in a conveyance direction is surrounded by a thermal insulation wall, air in the heating space flows into a space surrounded by the thermal insulation wall, and a decrease in temperature of the conveyance body of the conveyance portion is suppressed to improve thermal efficiency is disclosed (for example, Patent Document 1).